Technical Field
The present disclosure relates to an electronic device including a galvanic isolation module and to a manufacturing method of the same.
Description of the Related Art
In the field of galvanic isolation, for safety reasons, many power applications directly connected to high-voltage lines, such as systems for driving industrial machinery or household appliances, or control systems for motors and battery packs of electric vehicles, require decoupling between the power stage and the user control panel. Traditionally, in these applications, galvanic isolation has been obtained by optical couplers with isolation classes of several kilovolts and bandwidths of hundreds of kilohertz, or by coreless transformers on printed-circuit boards (PCBs).
In the field of integrated transformers for signal transmission, in order to obtain large bandwidths and reduce the size and costs, there have been recently introduced integrated coreless transformers. Design of transformers of this type requires the need to take into consideration numerous parameters, such as the breakdown voltage (also known as “dielectric rigidity”), the bandwidth, the time derivative of the voltage dV/dt, and the immunity to external fields.
In the field of integrated transformers for power transmission, in order to supply the driving system connected to the high-voltage power MOS transistor, it is desirable to use a power transmission line between the low-voltage (LV) portion and the high-voltage (HV) portion. In order to reduce the power losses and increase the efficiency of the system, it is important to reduce the resistance of the winding and the value of parasitic capacitance that is set up with the substrate. Currently, windings of a material with low resistance (typically, gold) and dedicated high-resistance substrates are used. This solution may not be employed in integrated circuits of a “smart power” type, with consequent increase in costs and loss of efficiency of the system as a whole.
There is hence felt the need for an integrated transformer that will overcome the drawbacks of the known art and in particular will make it possible to improve the isolation voltage class, will enable decoupling (galvanic isolation) between a low-voltage operating region and high-voltage operating region of the integrated circuit, will enable power transfer between the low-voltage operating region and the high-voltage operating region, and will, in general, enable a reduction of the costs and an improvement in performance.